1. General Background
This invention relates generally to a medication infusion device for administering fluid to patients and more particularly to an improved, ambulatory infusion device with a disposable administration set which is inexpensive to manufacture, convenient to operate and which ensures fluid delivery at a consistent and uniform rate. More specifically, this invention relates to an annunciator system for such an ambulatory infusion device which permits status data and the like to be audibilized. In addition to assisting a patient in controlling the infusion device, this feature permits a remote clinician to monitor the status of the device, accurately change infusion profiles and other device parameters, and diagnose alarm indications, all over normal telephone lines, and without special telephone equipment
2. Description of the Prior Art
As a result of the ongoing need for improved health care, there is a continuous effort to improve the administration of intravenous fluid to patients. As is well known, medication dispensers and infusion devices are used for infusion of predetermined amounts of medication into the body of a patient. Various types of medication dispensers employing different techniques for a variety of applications are known to exist.
In many cases it is of critical importance to provide precisely controlled and consistent flow rates of intravenous fluid to patients. This need for more controlled IV flow rates is only partially fulfilled by prior art pumps. Specifically, when a patient or nurse experiences a problem with a pump, they typically call a 24 hour "hotline" for clinical assistance. The called clinician is well versed on the proper operation of the infusion device and attempts to resolve the issue or reprogram the pump by asking the patient or nurse a variety of questions. For example, the clinician may inquire as to the current programming of the pump, the indicators or alarms that are being or have been displayed on the pump, as well as the status of the infusion. Status information may include, for example, how much medication has already been infused, how much of the current medicine dose has been infused, what has been the mean time between patient activated bolus requests, and the like.
The information relayed by the patient or nurse to the clinician is vital in order to properly determine whether there is a problem, to diagnose the problem if one exists, and to take the necessary corrective actions to remedy the problem or to reprogram the pump. The accuracy of the relayed information is critical, and misinformation could result in some instances, in serious patient injury.
This communication problem is often compounded by the fact that the patient, usually unattended by a clinician, is frequently under the effects of a narcotic, such as morphine, and possibly compromised from pain or other effects of the illness being treated. As a consequence of these or other factors, the patient's interpretation of the indications and program information, typically read from a small LCD display on the pump body, is sometimes incorrect. For example, the patient may fail to see or report a decimal point. Complicating matters further, many patients, especially diabetics, have compromised sight and are unable to read the LCD indications and program from the infusion device.
Even in circumstances where the assistance of a remote clinician is not needed, patients with impaired vision or perception, due to drugs or illness, often have difficulty assuring that they are correctly operating or programming the infusion device, or correctly interpreting alarm indications from the pump.
Existing pumps which use LCD displays to provide status information to the patient require that a compromise be made between pump portability, pump cost, and data clarity or completeness. In order to reduce cost, and to make ambulatory pumps as small and lightweight as possible, manufacturers must reduce the size of visual displays, such as LCD displays, as much as possible. Small displays, however, are difficult for patients to read, and will provide only two or three word outputs at any one time, compromising instruction or status understandability.